1. Field of the Invention
The present invention relates generally to arrangements for mounting loudspeakers and, in particular, to an adjustable, isolation mounting system for supporting a loudspeaker on an irregular surface, such as on top of a TV/monitor enclosure, and for isolating vibrations of the loudspeaker from the mounting surface.
2. Description of the Related Art
A loudspeaker operates by converting electrical energy into vibrational (sound) energy using one or more transducers. Transducers transmit vibrational energy through their frame, which is usually made of metal or plastic, into the walls of the loudspeaker cabinet. This vibrational energy propagates freely throughout the cabinet and may be introduced into the structure on which the loudspeaker cabinet is placed.
Center channel loudspeakers are typically used in home theater and audio/video systems to reproduce sound (usually dialogue) that should be centered on a TV/monitor screen. To obtain a centered sound effect, center channel loudspeakers are generally mounted on top of the TV/monitor enclosure or on a shelf centered above or below the TV/monitor. The center channel loudspeaker should be mounted as close to the center of the TV/monitor as possible to generate audio that sounds like it is coming from the center of the picture.
Center channel loudspeakers are usually small in size to make them practical to mount on a TV/monitor or bookshelf surface, and neutral in appearance so as to blend into the overall look of the TV/monitor. Center channel speakers usually have only midrange and upper frequency transducers because large bass frequencies cannot be produced without a large speaker cabinet, which is difficult to mount on top of a TV/monitor using conventional mounting arrangements.
There are several problems related to the use of center channel loudspeakers in a home theater or audio/video system. First, mounting of the loudspeaker on the top surface of a TV/monitor enclosure, which typically exhibits a very narrow flat ridge along the top front edge and an irregular, sometimes curved or sloping top surface, is often very difficult and unstable. Second, the listening axis from the speaker to the listener is usually not ideal (i.e., not 0 degrees). Third, the loudspeaker produces vibrational energy which is transmitted into the TV/monitor on which it is mounted, thereby causing noise and vibration within the TV/monitor enclosure.
Other manufacturers have dealt with these problems and issues only partially. Typically, four rubber feet are used to support center channel loudspeakers with a very shallow cabinet. Unfortunately, the use of four feet makes leveling the speaker on an irregular surface very difficult and, in some cases, impossible, especially if the rear two feet are not resting on the same flat surface as the front two feet. Usually, the rubber feet used are not truly isolating at the audio frequencies of importance, thereby yielding no significant reduction of transmitted vibrational energy. Typically, no provision has been made for altering the listening axis of the loudspeaker. Finally, the use of a shallow cabinet depth is not conducive to good sound quality due to internal cabinet reflections and standing wave phenomena. This last point is particularly important because the sound of the center channel loudspeaker must be of very high quality and tonally matched to that of the main loudspeakers.